Overproduction is one of the main factors affecting natural selection. Darwin believes many species overproduce to increase the likeliness of more offspring living and passing on their genes to more generations.
Hubble's brilliant observation was that the red shift of galaxies was directly proportional to the distance of the galaxy from earth. That meant that things farther away from Earth were moving away faster. In other words, the universe must be expanding.
Plants are producers and make their own food through a process of photosynthesis. Organisms are classified into domains according to shared characteristics.